Froome performed well in the Vuelta coming off the Tour and will be a major threat to Contador this year. At this point in time we can't consider Andy to be as big a threat, but based on his past climbing he remains a contender, and has 5 months to get himself together.
In top grade professional cycling (and in life) it is virtually impossible to be a major winner whilst being 100% clean (or honest). Most GC GT riders are simply doing what they love whilst playing the game.
I'm a huge Kloden fan (or a Klodist) - despite the fact that he's ridden for Telekom/T-Mobile, Astana and Radioshack
Plus I'm also a fanboy - of GT mountain stage previews from The Hitch
Contador at Fuente De - I salute you!